KABUL -- A U.S. military hit list of about 50 suspected drug kingpins is drawing fierce opposition from Afghan officials, who say it could undermine their fragile justice system and trigger a backlash against foreign troops.

The U.S. military and NATO officials have authorized their forces to kill or capture individuals on the list, which was drafted within the past year as part of NATO's new strategy to combat drug operations that finance the Taliban. The list is thought to include people with close ties to the Afghan government and others who have served as intelligence assets for the CIA and the U.S. military, according to current and former U.S. and Afghan officials.

Afghan counternarcotics officials expressed frustration that U.S. and NATO military leaders have refused to divulge the names on the list, a decision that they said could undercut joint operations to hunt down opium traffickers.

Gen. Mohammad Daud Daud, Afghanistan's deputy interior minister for counternarcotics efforts, praised U.S. and British special forces for their help recently in destroying drug labs and stashes of opium. But he said he worried that foreign troops would now act on their own to kill suspected drug lords, based on secret evidence, instead of handing them over for trial.

"They should respect our law, our constitution and our legal codes," Daud said. "We have a commitment to arrest these people on our own."

For years, the NATO-led military coalition in Afghanistan ignored the opium trade, saying their mission was to fight the Taliban and al-Qaeda, not drug dealers. Afghanistan's poppy fields supply about 90 percent of the world's opium.

At a meeting in Budapest last October, however, NATO defense ministers reversed their strategy and authorized their forces to confiscate narcotics and target drug labs as well as kingpins who provide monetary or other support to the Taliban.

Target list of 50

Since then, the U.S. military has developed a target list of about 50 drug kingpins thought to support the insurgency and has ruled that they can be killed or captured "on the battlefield," according to a Senate Foreign Relations Committee report released in August.

Two unnamed U.S. generals in Afghanistan told the committee's staff members that the list complies with international law and the U.S. military's rules of engagement because it contains only drug lords with "proven links" to the insurgency. To add someone to the list, the Pentagon requires "two verifiable human sources and substantial additional evidence," according to the Senate report.

U.S. Army Col. Wayne M. Shanks, chief of public affairs for coalition forces in Afghanistan, declined to answer questions about the list or to say whether anyone on it has been killed or captured.

The military "is concerned when we see a nexus between insurgent activity or financing and drug trafficking in Afghanistan," he said in an e-mail. "We regularly conduct operations to limit the insurgents' ability to intimidate, or otherwise threaten the Afghan people."